Online tech university Udacity is taking a radical approach to upping enrollment and retention for its courses: A 50 percent tuition refund. Those who successfully complete a Udacity "nanodegree" will get half their money back, provided they graduate within 12 months of the enrollment date.

It's yet another sign of the growing ambitions of the code-camp crowd, looking to supplant the need for time-consuming and costly computer science degrees of debatable value. But microcertifications, despite the appealingly low cost, may be too fast a track for both employers and employees.

Just enough of a degree

Nanodegrees, aka microcertifications, are a relatively new wrinkle in online IT accreditation. Awarded mainly by coding academies, boot camps, and other third-party IT education institutions, microcertifications are meant to focus on a relatively vertical skill -- Android development, for instance, or data analytics -- and get people up to speed on it in a practical way.

Prerequisites for the courses vary. The introduction to programming course, for instance, doesn't demand much more than rudimentary computer literacy. For the data analyst course, though, familiarity with Python and statistics generally are strongly recommended.

The missing pieces

There isn't much secret to the idea that nanodegrees are useful to both students and to employers or recruiters. For the former, they provide a quick way to assimilate a topic; for the latter, they provide a prescreening and precertification mechanism. Such screening is valuable. Business Insider's Matt Weinberger theorized that Apple and Google invented their own programming languages -- Swift and Go, respectively -- as a way to prescreen and pretrain Apple and Google employees.

Less clear is whether or not the training provided or the prerequisites demanded go deep enough. Data science, for instance, isn't simply a matter of knowing the nuts and bolts of statistics. It's also about being trained to ask next-order questions or understand how data-science techniques are applied in multiple fields -- as per the students of Eric Horn at the Data Sciences Summer Institute at the University of Illinois at Urbana-Champaign.

One implication of the "micro" in microcertifications: Such courses aren't meant to be comprehensive; they're only intended to suffice for a sufficiently motivated student to get up and running on the subject matter. But as InfoWorld's Eric Knorr pointed out in his overview of the microcertification landscape, these assays are no substitute for the deeper testing and verification that take time. If employers are as starved for skilled developers as they claim, they might be doing themselves a long-term injustice by leveraging microcertifications as a recruiting funnel.